I noticed on the Pokemon Wiki recently that the Icon that typically shows up in the top-left corner of the Wiki wasn't there. At the time I didn't think anything of it, but after checking a few other Wikis, I don't think that's the case.

Other affected Wikis include Fallout, Okami, Magic: The Gathering, Mario, and Metroid, amongst others that could be dealing with the same thing (didn't check all the Wikis).